Cab switch



Aug. 17, 192s. 1,596,189

J. J.l KENNEDY Ef AL CAB SWITCH l Original Filed Dec. 20, 1923 2SheetsSheet, 2

w ATTORNEY Patented Aug. 17, 1926.

l UNITED STATES PATENT OFFICE.-

JOHN J'. KENNEDY A ND CHARLES W. DARE, 0Fl CHICAGO, ILLINOIS, ASSIGNOBST0 THE PYLE-NATIONAL COMYANY, OF CHICAGO, ILLINOIS, A CORPORATION F N'EWJERSEY. f

CAB SWITCH.

Original application 1ed- December 20, ,1923, Serial No. 681,789.Divided and this yapplication led f November 10, 1924.

Our invention relates to` improvements in a cab switch and dimmer korcompensation switch for locomotive electric headlights.

It has for one object to provide a new and I improved form of switchwhereby the engineer may control the electric headlight.

Another ob'ect is to provide a switch Wherein the headlight may beturned on or off or dimmed dependent vupon the driving conditions.Another object is to provide a durable, compact and convenient switchwhich will retain proper adjustment at all times. Other objects willappear from time to time throughout the specication.

Our invention is illustrated more or less diagrammatically in theaccompanying drawings, wherein:

Figure l is a plan view;

Figure 2 is anelevation looking in the' direction of the arrow in Figurel;

Figure 3 is a bottom plan view;

Figure 4 is a wiring diagram.

Like parts are indicated by like characters throughout the specificationand drawings.

A is an insulating baseof hard rubber, bakelite, or similar materialadapted to be mounted at any suitable point in the cab. A1, A2 areconductors leading to the lamp and to the source of power and in serieswith the lamp and power source. A8 is a pivot for the switch arm. It iselectrically connected by means of a conductor bar A* and bindin post A5with the conductor A1. A6 is e switch arm mounted on the pivot Aa havingan insulated handle A. switch arm may bek itself a conductor or it may,as indicated, have a conducting element As on its undersidecommunicating with the pivot A3 and extending downwardly toward thehandle A7.. A9 is a quadrant mounted on the basek A and in slidableenga-gement with the upper side of the handle A". This quadrant may orma not be of insulating material. The qua,- rant is marked as indicatedwith the words Off, Dim, and On as indicating the operation of theswitch in its various positions. in relation to the operator.

B isa resistance coil or dimmer comprising a supporting base containingresistance The f Serial No. 748,886.

wire, the. particular arrangement of the wire forming no art of theinvention. Suflice it to say that t e resistance isA suiiicient to dimthe light as desired. B1 is a binding post for the conductor A. Thisbindin post extends down through the base A an communicates with theY-shaped flat conductor bark B2 recessed in the bottom of the panel A.One arm of this conductor bar communicates with one terminal oftheresistance element as at B3, the other arm communicates with the contactsegment B" by means of a conducting screw Bi which passes up through thebody of the panel, This conductor segment B4 is mounted on the panel A,and notched. as at B4 so as to make a yielding spring engagement withthe arm A and to hold it in the on position against vibration. Bit is adimmer contact segment mounted on the face of the base A, notched as atB7 to yieldingly hold vthe switch arm A6 in the dim position. Thissegment overlaps the segment B* so that as thev switch arm'L is moved tothe right, it comes in contact with the on segment B before itdisengages from the dimmer segment B6 so as to prevent surging in thecircuit. The segment B6 communicates by means of a screw B7 with theconductor bar B8 recessed in the bottom of they panel? A, which bar in'turn communicates with a screw B9 and the opposed terminal of theresistance element B. g

With the partsv inthe positionVY shown'in Figures 1, 2 and 3, the lig tis dimmed, the current ypasses from the conductor' A1 through bindingpost' A5, conductor A", switch arm A, shoe As, segment B6, screw B7,conductor B8, screw' B", through the dimmer resistance coil B, screw B3,conductor B2, binding post B1v tothe conductor A and' the current forthe light is then in circuit through the dimmer and a dim light isshown.

AsA the switch arm is moved to the right itV first disengages from thespringy held notched in the segment BB' and travels along the segment,the light beingy stilldim until the shoe A.el engages the segment` B".At this time the dimmer is in parallel and short Cil circuited, the pathof the current being as above indicated through the dimmer and also fromthe conductor A1, through binding post A5, conductor A4, screw A3, armA, shoe Jrs, segment B4, screw B5, conductor B2, binding post B1 and tothe conductor A". Further movement of the switch lever to the right willcause the shoe A8 to engage the notch B5 and will break the circuitthrough the resistance element. The engagement of the shoe with thenotch holds the switch in the i on position and current will continue topass directly through the lamp without passing through the resistanceelement.

C is a dead terminal segment on the face of the panel A. It is notchedat 1 to pro vide yielding means for holding the lever arm in the offposition and prevent its dropping down under vibration. All the segmentsproject upwardly from the face of the panel A and yieldingly force theswitch arm up against the quadrant A" and being notched provide springlocking elements to prevent vibration or jarring or dropping of theswitch arm from one position to another except when actually operated bythe engineer.

The shoe A8 may or may not be a spring. 1f it is a spring, it will servethe same function as the spring contact segments B1, B6 and C and undersome conditions they need not be springs. In other words, as long asthere is a spring engagement between the switch arm and the contactsegments, which spring engagement holds the arm against the quadrant andholds part of the arm against the segments and locks the parts togetherwhen the arm is in line with the notches in the segment, there issuliicient, and one or the other or both the segments or the shoe on thearm may serve as a spring.

Experience shows that it is frequently difficult in actual practice tomaintain constant voltage regulation of a locomotive headlight generatorand it sometimes happens that when a headlight is off, the generatorspeeds up and the voltage will rise as much as five or sinv volts. Ifthe switch is suddenly closed and the over voltage thrown onto the lamp,and the lamp will ultimately burn out and therefore, itis desirable,esgecially since a dimmer is necessary anyway in lighting the lightafter it has been off to first throw a dimmer resistance into thecircuit so as to load the generator, reduce the speed, and bring thevoltage down to normal, the resistance holding the voltage down untilnormal speed has been reached, thus breaking the light. Our switch ispeculiarly well adapted to perform this function because when the switchis moved from the off position toward the on position, the resistance iscut and the light burns dim for an appreciable length of time while theoperator is moving the lever across. As the lever or switch arm moveson, a time is soon reached when, without interrupting the dimmerresistance, there is a direct connection short circuiting the dimmerdirectly through the light, thus protecting the light against suoli overvoltage and avoiding surging in the circuit.

D is a motor generator set preferably mounted on a locomotive boiler andcontaining within the housing any suitable type of steam governor. D1 isa steam line by which boiler steam is fed to the generator set. D2 is aconductor leading from the generator set to the incandescent motorheadlight D". The conductor A2 leads from the binding post B1 on theswitch to the metal conductor A1 from the binding post A5 on the switchto the motor generator set.

It will be evident that while we have shown an operative device, stillmany changes might be made in the size, shape and arrangement of partswithout departing materially from the spirit of our invention and wewish, therefore, that our draw ings be regarded as in a sensediagrammatic.

This application is a division of my copending application Serial Number681,789, tiled December 20, 1923.

Wie claim:

l. A switch for locomotive headlights comprising a panel, a switch armpivoted thereon, a guide quadrant therefor and a plurality of contactsegments adapted to yieldingly engage the arm as it is forced upwardlyagainst the quadrant and held in position, a resistance element, aplurality of binding posts, one of them connected to the switch arm, theother connected to one of the contact segment-s and to one end of theresistance element, electric connection between the other contactsegmentand the opposed end of the resistance element, said live contactsegments overlapping to permit simultaneous engagement with the switcharm.

2. A. switch for locomotive headlights comprising a panel, a switch armpivoted thereon, a guide quadrant therefor and a plurality of contactsegments adapted to yieldingly engage the arm as it is forced upwardlyagainst the quadrant and held in position, a resistance element, aplurality of binding posts, one of them connected to the switch arm,the. other connected to one of the contact segments and to one end ofthe resistance element, electric connection between the other contactsegment and the opposed end of the resistance element, said live contactsegments over-lapping to permit simultaneous engagement with the switcharm, each of said segments being notched at a point removed from theposition of simultaneous engagement with the switch arm.

3. A control switch for locomotive headlights comprising a resistanceelement, a

Switch arm and Contact segments, one of them connected to the resistanceelement, the other connected directly to the circuit, the segmentsoverlapping to permit simultaneous engagement with the switch arm.

4. A1 switch for locomotive headlights comprising an insulating panel, aswitch arm pivoted thereon, a guide quadrant adapted to be engaged onits under side by the switch arm and a plurality of spring contactsegments engaging the under side of the arm and yieldingly holding itagainst the quadrant, a resistance element mounted on the panel abovethe switch arm, and a plurality of binding posts on the panel, a

conductor joining one of them and the pivotpoint of the switch arm, aconductor recessed in the bottom ofthe panel and joining the otherbinding ost and one end of the resistance element an one of thesegments, a conductor recessed in the under side of the panel joiningthe other end of the resistance element and one of the segments.

5. A switch for locomotive headlights comprising an insulating panel, aswitch arm pivoted thereon, a guide quadrant adapted to be engaged onits under side by the switch arm and a plurality of spring Contactsegments engaging the under side of ythe arm and yieldingly holding itagainst the quadrant, a resistance element mounted on the panel abovethe switch arm, and a plurality of binding posts on the panel, aconductor joining one of them and the `pivot point of the switch arm, aconductor joining the other binding post and one end of the resistanceelement and one of the segments, a conductor joining the other end ofthe resistance element and one of the segments.

Signed at Chicago, county of Cook and State of Illinois, this 16th dayof April 1926.

JOHN J. KENNEDY. CHARLES lV. DAKE.

